Congrats

Is your limit on air? Mine (same step) tops out at 4100mhz too:



I have an almost identical config (P5B Dlx w/o mods, Tuniq...).

I can do 4200mhz max screenshot (see sig) so you should do almost the same if not more

Tell us how is it going subzero, i´m planning to put it on SS in a few days & i´m curious to see how much can scale